package com.bluetooth;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBHelper extends SQLiteOpenHelper
{
	private static final String DATABASE_NAME = "test.db";
	private static final int DATABASE_VERSION = 1;
	public DBHelper(Context context)
	{
		//CursorFactory设置为null,使用默认值
		super(context, DATABASE_NAME, null, DATABASE_VERSION);

	}
	//数据库第一次被创建时onCreate会被调用
	@Override
	public void onCreate(SQLiteDatabase db)
	{
		String sql = "CREATE TABLE IF NOT EXISTS person(_id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, age INTEGER, info TEXT)";
		db.execSQL(sql);
	}
	//如果DATABASE_VERSION值被改为2,系统发现现有数据库版本不同,即会调用onUpgrade
	//数据备份
	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
	{
		db.execSQL("ALTER TABLE person ADD COLUMN other STRING");
	}

}
